On a new type of rational and highly convergent series, by which the ratio of the periphery to the diameter is able to be expressed
According to Eneström, Euler begins with an examination of the identity â« (2+2x+x2)/(4+x2) dx = arctan[x/(2–x)].
Original Source Citation
Nova Acta Academiae Scientiarum Imperialis Petropolitanae, Volume 11, pp. 150-154.
Opera Omnia Citation
Series 1, Volume 16B, pp.21-27.